Running WP on subdomain

Your permalinks don’t appear to be working correctly. Check your .htaccess file and see if it has the correct permissions, then update your permalinks structure.

The reason it’s going to the main page of your site is because any “not found” URL appears to redirect to the main page.

My URIs are:
https://www.allriga.com/latvianews

I have coppied from somebody .htaccess file.

RewriteEngine On
RewriteBase /
RewriteRule ^category/(.*)/(feed|rdf|rss|rss2|atom)/?$ /wp-feed.php?category_name=$1&feed=$2 [QSA]
RewriteRule ^category/?(.*) /index.php?category_name=$1 [QSA]
RewriteRule ^author/(.*)/(feed|rdf|rss|rss2|atom)/?$ /wp-feed.php?author_name=$1&feed=$2 [QSA]
RewriteRule ^author/?(.*) /index.php?author_name=$1 [QSA]
RewriteRule ^([_0-9a-z-]+).htm([0-9]+)?/?$ /index.php?name=$1&page=$2 [QSA]
RewriteRule ^([_0-9a-z-]+).htm/(feed|rdf|rss|rss2|atom)/?$ /wp-feed.php?name=$1&feed=$2 [QSA]
RewriteRule ^([_0-9a-z-]+).htm/trackback/?$ /wp-trackback.php?name=$1 [QSA]
RewriteRule ^feed/?([_0-9a-z-]+)?/?$ /wp-feed.php?feed=$1 [QSA]
RewriteRule ^comments/feed/?([_0-9a-z-]+)?/?$ /wp-feed.php?feed=$1&withcomments=1 [QSA]

Could you tell what needs to be changed and how.

That does not look like .htaccess file rules produced by WordPress 2.x. Copying from someone elses file is probably producing a conflict.

WordPress can create the .htaccess rules for your permalink structure if it can write to the file, I suggest you check the permissions on the file and remove the code you inserted.

Could you post me your .htaccess

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>

# END WordPress

Pfff, I just don’t get how can it be?! Why does it show my home page all the time?!

I’ve changed blog URL, it got better, but now I get an Error 404 – Not Found on the blog’s main page

All done! Everything works fine! ??

Your blog url is currently https://allriga.com/latvianews/ and not https://www.allriga.com/latvianews/ which is where your links point to.

Looks like an issue in your hosting / wp install. You need to select one form of the url (either with www or not) and make everything consistent with this.